Method and apparatus for forming and collecting fibers into an improved pipe covering



3,063,887 LECTING D. LA BINO TUS Nov. 13, 1962 METHOD AND APPARA FOR FORMING AND COL FIBERS INTO AN IMPROVED PIPE COVERING l2 Sheets-Sheet 1 Filed March 3, 1958 INVENTOR. Q9mww4o?m I zeegd .e

ATTORNEYS Nov. 13, 1962 D. LABINO 3,063,387

METHOD AND APPARATUS FOR FORMING AND COLLECTING FIBERS INTO AN IMPROVED PIPE COVERING Filed March 3, 1958 12 Sheets-Sheet 2 X E 2 @MJ $2 R 2 I WW4 e, om I w: E 2 Q flaw/on S own J 5 3 ,9 Ll la 5 O I G 0 O m: I mm o y. I v w: 8., Q 3 N mm 2; 3n w l 2. m: a: v mm 3 E 2 E Rm Q M B\ H a, QWN U M Sm Wk RN m Q t a 3 Q m A TTORNE YS D. LABINO Nov. 13, 1962 ,063,887 METHOD AND APPARATUS FOR FORMING AND COLLECTING FIBERS INTO AN IMPROVED PIPE COVERING 12 Sheets-Sheet 3 Filed March 5, 1958 INVEIVTOR. M rub? $366 -e ATTORNEYS 12 Sheets-Sheet 4 D. LA BINO US FOR FORMING AND CO FIBERS INTO AN I MPROVED PIPE COVER METHOD AND APPARAT Nov. 13, 1962 Filed March 3, 1958 & is Y 0 T E QM N E E R V O n A e 8 & 3 9 9 5 N a 3 aur 5 Y. F a M 35 3 B a 3 K m m. e 4 2 w 3 7 8 w 4 9 7\ 8 9 3 2 M% 6 m I 9 I 1.. [l1 w 7% I 4 m 00 I! w mu. w :2: 14 9 7 6 7 Nov. 13, 1962 D. LABIN 3,063,887

METHOD AND APPARATUS FOR FORMING AND COLLECTING FIBERS INTO AN IMPROVED PIPE COVERING Filed March 3, 1958 12 Sheets-Sheet 5 INVENTOR.

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METHOD AND APPARATUS FOR FORMING AND COLLECTING FIBERS INTO AN IMPROVED PIPE COVERING 12 Sheets-Sheet 7 Filed March 3, 1958 INVENTOR.

zegwz ATTORNEYS D. LABINO US Nov. 13, 1962 3,063,887 METHOD AND APPARAT FoR FORMING AND COLLECTING FIBERs INTO AN IMPROVED PIPE COVERING l2 Sheets-Sheet 8 Filed March 3, 1958 INVENTOR. Bifgflmmcaowa fid efl -e ATTORNEYS D. LABINO Nov. 13, 1962 ,063,887 METHOD AND APPARATUS FOR FORMING AND COLLECTING FIBERS INTO AN IMPROVED PIPE COVERING l2 Sheets-Sheet 9 Filed March 3, 1958 INVEN TOR. 490mm 0425010 BY zodeggw -e ATTORNEYS D. LABINO Nov. 13, 1962 3,063,887 METHOD AND APPARATUS FOR FORMING AND COLLECTING FIBERS INTO AN IMPROVED PIPE COVERING l2 Sheets-Sheet 10 Filed March 3, 1958 I I 1 7 r INVENTOR. WOQZMQ %&46 K J tad 1e ATTORNEYS Nov. 13, 1962 D. LABIN 3,063,887

METHOD AND APPARATUS FOR FORMING AND COLLECTING FIBERS INTO AN IMPROVED PIPE COVERING Filed March 5, 1958 12 Sheets-Sheet 11 IN VEN TOR.

ATTORNEYS N v- 13, 1962 ABINO 3 063,887

D. L 9 METHOD AND APPARATUS FOR FORMING AND COLLECTING FIBERS INTO AN IMPROVED PIPE COVERING Filed March 3, 1958 12 Sheets-Sheet 12 IN V EN TOR.

81 @MefJzWz A TTORNE YS United States Patent )fifice 3,063,887 Patented Nov. 13, 1962 METHOD AND APPARATUS FOR FORK [ENG AND COLLECTING FIBERS INTO AN IMPROVED PIPE COVERING Dominick Labino, Grand Rapids, Ohio, assignor, by mesne assignments, to .iohns-Manville Fiber Glass Inc., Cleveland, Ohio, a corporation of Delaware Filed Mar. 3, 1958, Ser. No. 718,636 6 Claims. (Cl. 15637) This invention relates to an improved pipe covering or fibrous casing which is to be utilized for thermal insulation and to a method and apparatus for making the same.

The pipe coverings of the prior art which heretofore have been used as thermal insulators may be said to fall into basically two general classes.

The first class is composed of the type of pipe coverings in which the insulating material is composed either of bulk substances, comprising loosely integrated fibrous or granular material, or flexible mats. These loosely packed or flexible forms are normally held in place by suitable retention means since they themselves do not possess the capability of shape retention. In practice, these flexible forms are either wrapped about or helically wound about a pipe and encased either by sheet metal, metal mesh, plastic or paperboard envelopes or sleeves placed around the material and brought into covering position about the pipe. The second class of materials comprises those which are slightly more rigid and consists both of the fabricated forms and the molded forms. The coverings in this latter class are conventionally made and placed about the pipe in two circumferential halves or semicircular portions. Again, it is conventional to supply an envelope, jacket, or other suitable retention device to secure these molded or fabricated forms into their position covering the pipe.

All of the pipe coverings as discussed are relatively heavy and in addition, these fabricated and molded forms are particularly limited in use by reason of the fact that their inside diameter dimension, which fixedly determines the size and shape of the pipe which may be insulated, is not easily changed. These and other basic limitations of the molded type of pipe covering are discussed in detail in the patent to Stephens, No. 2,778,759, dated January 22, 1957, wherein to overcome these limitations an improved pipe covering is described which is illustrated in FIG. 1 herein. It was found that by controlling the diameter and length of the glass fibers forming the fibrous casing within predetermined limits, by controlling the weight of the binder with respect to the Weight of the finished product within predetermined limits and by controlling the density to which the product is compressed during the molding thereof, an improved thermal pipe insulation was obtainable.

However, the demands of present commercial practice presents many additional factors which cannot be met either by the apparatus or the methods of the presently known art.

When using an apparatus which depends upon molds to form the pipe covering, it is necessary to roll the fibrous mat about a mandrel and insert the mandrel Within a mold formed of two halves. The mold is then closed about this mat on the mandrel and one end of the mold is sealed off while gases, from a suitable source such as a gas fired oven, are fed into the interior of the mandrel. These hot gases set the resin, drive off moisture and cure the covering. Whether or not the formed uncured cylindrical mat is cured by means of a perforated mandrel or is inserted into an appropriate oven would be a matter of choice. However, by the use of a mold to form the configuration of the cylindrical pipe covering, a number of important limitations both as to manufacturing tolerances and manufacturing flexibility are introduced.

In using a mold there is no way in which the critical dimensions of the thermal insulation may be varied without the substitution of a complete new set of molds for a selected size of pipe. This would mean that should there be desired a variation in either the inside diameter of the pipe covering, in the wall thickness of the covering or in the outside diameter of the pipe covering, there would have to be a complete substitution of at least a new size mold and in some instances both a new mold and a new mandrel. In present commercial practices in the manufacture of pipe coverings, there is an ever increasing demand for variations of all the three dimensions of the pipe covering, both its inside dimension, its wall thickness and its outside dimension. Accordingly, the mold method of manufacturing thermal pipe coverings by reason of necessity of replacement of molds and a requirement of keeping an extensive supply of mold sizes available, in combination with varying sized mandrels, has presented a most cumbersome and even burdensome storage problem that necessarily has had a detrimental eifect on the flexible quantity and quality of the resultant product.

Additionally, a mold when clamped upon a fibrous mat or wrapped about a mandrel, at the mating point of the two cylindrical halves, will form in the fibrous mat a lon gitudinal ridge, particularly since the fitting tolerances of the two portions or halves of the mold would be almost impossible to maintain in perfect fit over a pro longed period of time with extensive use. These irregularities in the outer surface of the mat would have to be subsequently removed by either grinding or other treatment in order to present a smooth outer peripheral surface.

When using a mold and mandrel combination, it has been found extremely difficult to maintain proper alignment between the absolute center of the mandrel and the absolute center of the molds along the entire longitudinal center line of the mandrel. This centering between the mold and the mandrel is extremely important as it is essential that the pipe covering, when formed, present equal insulating resistance to a loss of heat of its enclosed pipe in all directions. It is well understood that a pipe covering, for example, which had a variable wall thickness, would present a greater resistance to the loss of heat through those portions of the covering having the greatest wall thickness. These relatively thicker wall portions would be formed when the material contained within the mold was subjected to unequal pressures either through the medium of a mold forming device or by reason of the fact that the mold was not centered with respect to the longitudinal center line of the mandrel. No matter what the cause of the formation of the thicker portions,

it would naturally follow that the presence of areas of greater wall thickness would mean the introduction of walled areas of a reduced thickness in another portion of the covering.

By having walled areas of varying thicknesses it would be imposisble to secure equal insulaing resistance about all portions of the pipe covering and the resulting imperfections would prove a serious limitation in the commercial application of the product. Further, if the longitudinal center lines of the mold and the mandrel were not coincident, variations in the shape and size of the inside diameter of the opening through the pipe covering would occur throughout the length of the covering resulting in something less than a perfect fit for the covering about a pipe. This would be true although the covering is to some extent flexible, because the covering must necessarily have certain properties of substantially rigid form. These variations in the inner diameter, particularly in the treament of the smaller pipe sizes, have proven to be an important limitation in the pipe coverings of the prior art.

It is highly desirable, therefore, in the manufacture of the pipe coverings to secure, as closely as possible, uniformity 'in the wall thickness of the pipe and uniformity pf the inside diameter of the pipe covering as well as the hereinbefore discussed uniformity of the outside dimension and constant density. By controlling all these factors a pipe covering will result that is perfectly even in its dimensional form. All of the dimensions will be symmetrically formed about the center axis of the pipe covering and the wall thickness will be constant thereby forming a concentric ring, of equal thickness throughout, about a longitudinal line through the center of the opening in the covering. Therefore, constant pipe covering characteristics maybe selected that will remain substantially the same overa considerable period of prolonged operations but yet are alterable if desired.

It is an important object of the present invention to form a fibrous casing under controlled conditions of temperature and pressure.

Another object of this invention is to form a fibrous covering from a fibrous mat impregnated with an unactivated binder and to activate the binder incrementally.

Another object of the invention is to form a fibrous casing from a fibrous mat impregnated with an unacti- .vated binder and to incrementally activate the binder by initially activating the binder in the peripheral surface area of the casing to form an outer shell about the casing and subsequently to activate the remaining binder in the casing.

Another object of the invention is to direct pressure against the peripheral surface area simultaneously when activating the binder.

Another object of the invention is to direct pressure against the peripheral surface area of the casing while activating the remaining binder in the casing.

Another object of the invention is to direct pressure to the fibrous mat while wrapping the mat about a rotating mandrel to initially blend the fibrous mat throughout the length of the casing.

It is yet another object of the present invention to direct pressure to the peripheral surface of the casing after it is wrapped before activating the binder to smooth the peripheral surface of the casing.

It is still another object of the present invention to rotate the fibrous casing wrapped about the mandrel by rotating the mandrel while activating the binder on the peripheral surface area of the casing.

It is further another object of the present invention to rotate the fibrous. casing by rotating the mandrel while activating the binder throughout the fibrous mat. It is accordingly an object of the present invention to provide an improved apparatus to form a fibrous casing or pipe covering wherein all the thickness dimensions of the pipe coverings are selectively adjustable with a minimum of operational delay.

It is another object of the present invention to provide apipe covering machine wherein the operation between all elements is timed so that the machine is continuous and automatic whereby the production of the pipe coverin gs is uninterrupted.

It is yet another object of the present invention to provide a method of producing a pipe covering wherein the percentage of binder material is maintained at a minimum within the fibrous mat.

It is yet another object of the invention to provide a pipe covering wherein the density of the homogeneous fibers of the mat will be maintained uniform despite any change in either inside diameter, outside diameter or wall thickness of the resilient covering. 7

Other objects and advantages of the invention will 4 become more apparent during the course of the following description when taken in connection with the accompanying drawings.

In the drawings, wherein like numerals are employed to designate like parts throughout the same:

FIG. 1 is a perspective view of a fibrous casing made according to the method and apparatus of the present invention;

FIG. 2 is a side elevation of the interconnected element forming the complete apparatus;

FIG. 3 is an enlarged side elevation partly in section and with parts broken away of the conveyor reversing mechanism as illustrated in FIG. 2;

FIG. 4 is a sectional view with parts broken away taken along the line 4-4 of FIG. 3;

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 2;

FIG. 6 is a sectional view taken along the line 6--'6 of FIG. 5

FIG. 7 is a side elevation of the wrapping, ironing and binder activating portions of the apparatus as illustrated in FIG. 2;

FIG. 8 is a sectional view with parts broken away taken along the line 8-8 of MG. 2;

FIG. 9 is a sectional view taken along the line 9--9 of FIG. 8;

FIG. 10 is a sectional view taken along the line 1010 of FIG. 8;

FIG. 11 is a sectional view taken along the line 1111 of FIG. 12;

FIG. 12 is a sectional view with parts broken away taken along the line 12-12 of FIG. 8;

FIG. 13 is an enlarged fragmentary detail view with parts broken away and parts shown in section of the gear arrangement on a drive shaft operating the mandrel rotating shaft;

FIG. 14 is a sectional view taken along the line 1414 of FIG. 10 with parts broken away;

FIG. 15 is an enlarged fragmentary sectional view with parts broken away taken along the line 15-45 of FIG. 14;

FIG. 16 is an enlarged elevation view of the timing mechanism as illustrated in the lefthand portion of 'FIG.

FIG. 17 is an enlarged sectional view taken along the line 17-l7 of FIG. 16;and

FIG. 18 is a schematic wiring diagram of the electrical circuit of the timing mechanism.

in general, this invention contemplates forming a thermal pipe insulation fibrous casing or conduit from a mat of glass fibers, bonded with a binder, which may be used for thermal pipe insulation and wherein the binder is activated to fixedly form the casing after the mat is first formed into a desired shape. The pipe insulations which are formed from this invention are normally cylindrical and are easily controlled as to quality standards by reason of the interdependence of the apparatus employed with the method of production to allow full maximum control of these quality standards and at the same time provide maximum selection of desired variations in production tolerances. Thus, important maximum flexibility of these tolerances is secured so that the product may be produced to meet the ever changing quantity demands for different sizes and shapes of covering without losing the desirable product quality standards or production time. In the description which will hereinafter follow, the apparatus providing the objects of this invention will be presented in accordance with a number of the stations or stages which are indicated by portions of the machine as enumerated in FIG. 2. Generally and without, at this point, presenting a detailed description of either the apparatus of the process, these stages comprise the following: Station A, where primary fibers are blasted to produce secondary fibers which fall upon an endless belt and are simultaneously sprayed with a binding material to form a continuous and endless fiber mat; station B, where the endless mat formed of secondary fibers, in combination with the thermosetting binder or resin, is sheared into the desired lengths to be later employed to form the pipe covering of desired dimensions; station C, where these lengths of the fibrous mats are wrapped about a mandrel to form the uncured cylindrical casing of the desired dimensions; station D, where the uncured mat, in cylindrical form, wound about the mandrel passes through a first or initial stage of incremental binder activation, to activate the binder in at least the peripheral surface area of the casing; station E, where the casing having a portion in which the binder has been activated to bond the fibers in that portion to one another passes through a second stage of incremental binder activation to activate the remaining binder in the casing; station F, where the casing is positioned for unloading and conveying for further processing.

The pipe covering, as it is formed moving from stations A to F inclusive of the apparatus, undergoes a change from the primary strands of glass fibers at station A to the thermal insulation pipe covering, cylindrical in form, wherein all the fibers are bonded to one another which is delivered at station F. This apparatus is continuous and uninterrupted in its operation so that if the process of the present invention is practiced on a never ending continuous operating belt of materials, the production of the pipe coverings will likewise be continuous.

Turning now to a description of the apparatus comprising station A where the primary fibers are blasted to produce secondary fibers and sprayed with the binder to form a fiber mat and referring particularly to FIG. 2, there is shown a glass melting pot of clay, platinum or any suitable alloy for the heating and melting of glass marbles. The pot is circular and has a conventional aperture plate at its lower extremity provided with a plurality of concentrically arranged apertures adjacent the periphery thereof.

A plurality of streams of molten glass are attenuated from pot 10 into primary filaments 11 passing between and drawn by the coacting rollers 12, 13, it being understood that suitable drive means are provided for these rollers 12, 13. The rollers 12 and 13 draw the streams or primary strands 11 of glass fiber to the desired size and advance them at the desired rate, through suitable guide means 14, the extremities of the filaments 11 being directed by the guide means into the blast emanating from the burner 15. A combustible gas mixture is fed through the burner 15 to create a high speed blast of intense heat capable of melting and attenuating the primary filaments 11 to very fine fibers at a high rate. As the filaments 11 are fed into the blast, they are rendered fluid and drawn out by the force of the blast into very fine glass fibers.

It is well understood that the method and apparatus for making these glass fibers is shown in United States Patents No. 2,663,906, issued on December 29, 1953, to Dominick Labino, and No. 2,814,657, issued on November 26, 1957, to Dominick Labino. The indicated sizes of the fibers, attenuated by the gaseous blast, may be varied in many ways. The fibers in the instant case may be in the diameter range of between 1 /2 microns to 4 microns and preferably between 2 and 3 microns.

The fibers are directed by the blast to a suitable collecting means 16. These latter means include a continuous belt 17 or conveyor of wire mesh or other foraminous material capable of collecting and transporting the fibers directed thereon by the gaseous blast emitted from burner 15. The belt is supported along its pathway by a supporting framework indicated generally by 18. This framework 18 consists of a plurality of pairs of upright angle irons 19 and 2t). Only one angle iron from each pair appears at one side of the conveyor as shown in FIG. 2, it being understood that identical uprights appear on both sides of the conveyor path. These uprights may be innterconnected by suitable pairs of interconnecting cross angle irons 21 (only one shown) as desired for structural support.

The continuous belt 17 travels over a suction box 22 suitably mounted to angle iron 19 to cause a flow of 'air through the conveyor to aid in the deposition of the fibers, in the form of a mat 23, onto the conveyor 17. A series of binder applicators or nozzles 24, only one shown, may be disposed in the position as shown in FIG. 2 running transversely of the blast stream in order to coat the blasted fibers with a binder as they are being deposited or collected upon the endless conveyor 17. The binder or resin content as broadly recited is 5% to 14% of the mat weight as determined by ignition loss and is preferably about 10% or slightly below 10%. Additional nozzles 25 directing a fine spray of water are positioned as shown in FIG. 2 and when the conditions of humidity make it desirable may further introduce a fine spray of water or other liquid to the glass fibers as they are being collected to form the mat 23.

The source of the compression for the nozzles 24, 25 is not shown, it being understood that both the binder through nozzles 24 and water through nozzle 25 would be introduced under an air jet, or stream, provided with suitable regulating valves or other controls. As seen in FIG. 2, the conveyor belt 17 follows substantially a triangular path so that the mat 23 formed upon the long side 26 of the belt triangle thus formed, is carried up and over the high point of the conveyor and down the hypotenuse side 27 of the "belt triangle. Although the conveyor is formed as a triangle it is not intended to limit the invention in any way by this showing as other forms and configurations could be used. It has been found desirable, however, that when the mat is carried towards a subsequent station, in this case station B, that the conveyor side in proximity to the next processing station be sloping as is side 27 of the instant case.

The conveyor belt 17, in the embodiment shown, is mounted to freely rotatable shafts 28, 29, 3% which are conventionally mounted in journals or brackets afiixed to the angle iron bars 19, 26, hereinbefore described, comprising the framework 18 supportingthe belt 17. A plurality of rollers 31, 32, 33 respectively are keyed or otherwise fixedly mounted to the shafts 28, 29, 30 to support and to drive the belt 17. Other driving connections such as a gear and chain arrangement could be used instead of the friction rollers 31, 32 and 33 to support and to cause movement of this belt 17 without departing from the spirit of the invention.

A drive motor 34, resting on the floor of the structure housing the apparatus, is connected by means of a link chain 35 to a sprocket 36 which in the embodiment shown in FIG. 2 is fixed or keyed to shaft 30. This motor 34 through the chain 35' causes a rotation of shaft 30 and this rotation of shaft 3% through the medium of roller 33 is transmitted to the belt 17 so that belt 17 is driven at a consistent rate of speed in the direction of arrow 37 The rollers 31 and 32 about shafts 28 and 29, serve as suitable guide means to maintain the belt in proper alignment relative to the blast burner 15. The timing of the motor 34 which determines the speed of belt 17 is synchronized with the delivery of the stream of fibrous material from the blast burner 15 so that a continuous fibrous mat 23 is formed and carried by the belt 17 as it moves.

The fibrous mat 23, formed at station A, is led from the sloping side 27 of the triangle formed by belt 17 up and onto a table conveyor means generally indicated at 38 where it is led into station B. The conveyor means 38 includes two independent conveyor belts 39 and 40 each being formed of a suitable wire mesh or foraminous material which develops friction against the fibrous mat 23 so as to grip the mat and to pull and direct it along its path. At station B, this mat 23 is sheared, by means 2 to be hereinafter described, into segments of a predetermined length preparatory to its being further conveyed to station C where it is formed upon a mandrel into a cylindrical tube as will later be described.

The shearing at station B in the present invention is performed by a suitable knife edge. As will be hereinafter described, the action of the knife does not sever the mat but rather in cooperation with a reversing conveyor movement tears or rips the material to form a feathered or tapered edge of the segments of the mat as they are separated from the continuous belt of material. At station E, the fibrous mat is placed in tension by two independently driven conveyor belts, which at the m ment of the severance of each section, are moving in opposite directions. This conveyor action, creating a tension in the material, in combination with the simultaneous movement of the severing knife, which under positive pressure is directed downwardly, causes a ripping or tearing severance of the material. In this manner, the ends of the segments separated from the continuous belt are not out along a distinct vertical plane or line forming a smooth slice in the material, but rather the fibrous mat edges are feathered. This novel result is caused by the hereinabove discussed reversible action of the conveyor belts 39 and 40 with respect to each other acting in timed relationship with the cutting tool.

Referring now to FIGS. 2, 3 and 4, the framework 41 for conveyor means 38 includes a plurality of pairs of upright angle iron bars 4-2 and 43 only one bar from each pair being shown, which supports the conveyor 39 and similar bars 44 and 45 supporting conveyor 40. These upright pieces are interjoined by a first cross bar 46 connecting them at their lower portions and by a second cross bar 47 extending substantially longitudinally and parallel with respect to the line of conveyor movement but disposed outside of the belts 39, 49 forming the conveyor path. The belts 39 and 40 are mounted in normal tension by means of freely rotating shafts 48, 49, 50 and 51, two of said shafts supporting each belt. Suitable journal bearings such as that shown at 52, FIGS. 3 and 4, are mounted to the cross bar 47, of the conveyor supporting framework, to provide support for the shafts at a point outside of the line of conveyor movement.

The conveyor belt 40 travels constantly in the direction of arrow 53 under the action of a constant speed drive motor 54 which through a suitable chain 55 causes rotation of shaft 51 by driving the shaft 51 through the medium of suitable sprocket 56 fixed to the shaft. Rollers 57 and 58 mounted on the shafts 50, 51 respectively hold belt 40 in tension and the driving action of motor 54 is transmitted to the conveyor 40 by roller 58. It is understood that the means of transmitting the drive from the various shafts to the belts is conventional in all respects and since it does not form a part of the present invention, only those portions of the drive believed necessary for a clear understanding of the invention have been and will be herein discussed.

The belt 39 as seen in FIG. 2 independent of the belt 40, i driven by independent drive means. As will be later described, belt 39 normally moving the direction of arrow 59, accelerates in the direction of arrow 59 and also reverses to move in the direction of arrow 60, all in timed relationship to the action of the knife shearing means also to be later described.

The mat 23, as it is delivered from the downward sloping side 27 of the belt 17, forms a loop at 61 and is carried upwardly to come to rest upon the surface of conveyor belt 39 moving initially in the direction of arrow 59. At this time, both the belts 39 and 46 are moving in the same direction, that is in the direction of arrows 59 and 53 respectively. When the lead edge 62 of mat 23 has moved under and beyond'the vertical line 63, appearing in dot-dash (FIG. 6 that extends directly down- Wardly from the lower edge 64 of the knife blade-65,

the knife blade 65 will be caused to be directed downward in the direction of arrow '66 (FIG. 6) along the line 63 at the proper moment by adjustment of suitable timing means that will be later described.

Referring now to FIGS. 2, 5 and 6, the knife blade 65 is mounted at the lower extremity of an air piston rod 67 and receives its downward force from the double acting air cylinder 68 when compressed air is allowed to enter the cylinder 68. When the timing means directs air into cylinder 68, piston 67 is forced downward in the direction of the arrow 66 forcing the lower edge of knife 64 to extend below the substantially horizontal plane of mat 23. Referring to FIGS. 5 and 6, it is seen that the knife blade 65 extends transversely of the mat 23 and is supported so as to be substantially perpendicular to the path of the belts 39, 46 for the full width of the mat 23. Air cylinder 68 is affixed to cross plate 69 by welding or other suitable means and an opening 70 is provided substantially central of plate 69 to coincide with the axis of movement of piston rod 67 to allow freedom of travel for the piston rod 67 both upwardly and downwardly. A shoulder bearing 71 surrounds the opening and may be conventionally fitted into opening 76 either by friction t, a flange arrangement or welding It being well understood that any suitable means for mounting the cylinder 68, with its piston rod 67, on plate 69 may be used without departing from the spirit of this invention. Plate 69, be means of conventional angle irons 72 and 73, is supported above the plane of the conveyors and angle irons 72 and 73 are conventionally welded, one end to the plate 69 and the other end to the upper cross bar 47 of the supporting framework 41. As seen in FIG. 5, when the piston rod 67 is drawn into air cylinder 68, the lower edge 64 of the knife blade 65 is supported above and out of contact from the fibrous mat 23 passing across conveyors 39 and 40. Any conventional brackets 74 or welding may be used to fixedly mount the piston rod 67 to the knife 65 and if desired, guide means 74 laying closely adjacent the terminal face portions of the knife may be utilized to maintain the knife blade in its proper position perpendicular to the plane of the conveyors.

Referring again to FIGS. 2 and 6, it is seen that the belts 39 and 46 do not come into flush contact with each other but since shafts 49 and 50 are spread apart, an opening 75 directly below the downward acting knife 65 is formed. It is therefore seen that when the lower edge 64 of the knife 65 is forced downwardly in the direction of arrow 66, the knife 65 passes between the belts 39, 40 and through opening 75 and does not contact either the belt 39 or the belt 40.

When air cylinder 68 is activated through timing means to be later described to open the air cylinder valve (not shown) to direct compressed air into cylinder 68, the knife 65 will be forced downward to pass through the horizontal plane of the fibrous mat 23 between the two belts 39, 40 of the conveyor 38 at station B. At the time that the knife blade 65 is being forced downward, another portion of the timing means causes a reversal of direction of movement of the conveyor belt 39.

As was hereinabove described, conveyor 39 initially moves in the direction of arrow 59 forcing the fibrous mat 23 under and past the vertical plane determined by the line 63 extending below knife 65. When the knife descends under action of the air cylinder 68 at that same instant, the timing means will cause the conveyor 39 to reverse direction so that it will then move in the direction of arrow 60 FIGS. 2 and 6. This places the mat 1n tension before the blade 65 engages the mat 23 since one portion of the mat 23 is now acted upon by the conveyor belt &0 moving in the direction of arrow 53 while the other portion of the mat is acted upon by the belt 39 moving in the opposite direction as indicated by arrow 69. Therefore, when the knife 65 is forced downwards to sever or tear the mat 23 the mat 23 will be stretched in tension by'this counterdirectional tractive force. The

knife 65 as it passes through the fiber mat 23 is thereby assisted in severing the mat 23 since the cutting action of the knife 65 Wlll be augmented by the tearing or pulling action of the two belts 39, 40. This combination of downward force by the knife 65 and counterdirectional pulling action of the belts 39, 40 results in the hereinbefore mentioned tapered or feathered lead and trail ends of the severed mat.

When the fiber mat 23 has been severed and the knife 65 raised by positive action of the double acting air cylinder conveyor section 39 will be caused to reverse its direction and will move again in the direction of arrow 59. This allows the subsequent or succeeding portion of the mat 23 to be severed, to be led under the knife blade where it continues its movement in the direction of arrow 53 under the pull of conveyor 46. It is understood that each severed length of the mat 23, as shown in FIG. 2, continus to move in the direction of arrow 53 for further processing at station C under the action of the conveyor section 46 driven at a constant speed by motor 54. In addition to providing for the tapering of the ends, which will be hereinafter described as an advantage of this reversing action, this reversing of the conveyor 39 provides for a separation of the sections of the mat and is also timed, through suitable means to be hereinafter described, with the processing to be accomplished at station C so -that the individual mat sections will arrive in proper timed relationship with respect to each other and with respect to the other operating portions of the apparatus so that continued and uninterrupted operation will result. The reversing of conveyor section 39 is likewise timed to the downward stroke of the knife 65 and timed in cycle with the operations of other stations in the apparatus so that each one performs its operation on the mat in timed relationship with all the other sections or stations of the apparatus.

Referring now to FIGS. 2, 3 and 4, there is shown the reversing means 76 which provide for the hereinabove described reversing and accelerating action of conveyor belt 39. A link chain 77 positioned initially as shown in heavy lines, FIG. 3, extends from a sprocket 78 which is fixedly mounted to shaft 30, which is the lower shaft at the right end of the collection means 16. This chain 77 extends up to engage a sprocket 79 which is fixed to the shaft 48. The conveyor 39 is held in tension and travels along a path determined by rollers or sprockets 80, 81, as seen in FIGS. 2 and 3 and is keyed or suitably fixed to shafts 48, 49 respectively. Therefore as the drive motor 34, through the means of shaft 3%) herein before described, causes the belt 17 to move in the direction of arrow 37, FIGS. 2 and 3, this drive is transmitted by shaft 30 to the sprocket 78 to belt 77 and through sprocket 79 to rotate the shaft 48 and sprocket 80 to initially move the conveyor 39 in the direction of arrow 59. Referring now to FIGS. 3 and 4, from angle bar 42 of the supporting framework 41 of the conveyor means 38 or from a link extension 82 connected to bar 42 if desired, arms '84, 85 are pivotally mounted by means of a shaft 83. The arms, 84, 85 pivot as a unit being fixed in position relative to shaft 83. A vertical angle brace 86 is mounted by means of two cross braces 87, 88 welded or suitably fastened to upright angle extension iron 82, to position journals 89, 943 (FIG. 4) that hold shaft 83 for rotation. At the outer extremity of the arm 84 is a gear 91 mounted by means of a pin or stud 92 so as to be freely rotatable. The teeth of gear 91 engage the links of chain 77 on the outer surface of the periphery so that as the chain 77 moves in the direction of arrow 93 (FIG. 3), the gear 91 rotates in a counterclockwise direction as viewed in FIG. 3, ie in the direction of arrow 94. At another portion of the frame bar extension 82 is mounted an arm 95 by means of a shaft 96. This shaft 96 is supported from journals 97, 98 in the same manner as shaft 83 is supported by journals 89, 90. Arm 95 extends downwardly and at its extremity has a gear 99 similar to the aforementioned gear 91, mounted for rotation about pin 100. The teeth of gear 99 engage the belt or chain 77 on the inside at its periphery. A pair of bars 101, 102 welded to the angle iron 88 are provided to receive a shaft 193 which pivotably supports a double acting air cylinder 104. A spring 105 is fastened between the extremity of arm 95 and a cross brace 46 of the framework as shown in FIG. 4, so that a constant pressure in the direction of arrow 106 (FIG. 3) is applied. This pressure causes or holds the arm 95 in the heavy line position as shown in FIG. 3 and in the absence of any other force being applied will hold the belt 77 essentially in its heavy line position so that the arms 84, will be held in heavy line position as shown in FIG. 3. In this position the air cylinder 104 has been activated so that the piston rod 107 is fully extended. When the knife blade 65 as hereinbefore described is forced downward, the timing means will activate air cylinder 184 to sharply force the plunger 107 to move downward in the direction of arrow 108. Piston rod 107 having a bifurcated end 199 is fixedly connected by stud 116 to the extremity of arm 85 and forces arm 85 to suddenly move from its heavy line position of FIG. 3 to the dotted lin position of FIG. 3. Since arm 85 is operably engaged to arm 84, by common shaft 83, the arm 84 will likewise be drawn downward to its dotted line position as shown in FIG. 3. When this downward force is applied to the arm 84 it causes chain 77 to be moved from its heavy line position to the dotted line position of FIG. 3. Since the chain is of a predetermined length when this upper portion of the chain is pulled down by arm 84 the lower portion of the chain 77 will be pulled upwards to move from its heavy line position to the dotted line position as shown in FIG. 3. The resultant force of the action hereinabove described is sufficient to overcome the tension in spring 105 and the arm pivoting about the shaft 96 will be raised to its dotted position as chain 77 is raised. At this time the cylinder 104 pivots slightly from its full line position to its dotted line position and also at this moment since the chain 77 is moving at a constant speed in the direction of arrow 93, this change in the position of the chain 77 means that the chain 77 will travel a longer distance from the sprocket 78 to the sprocket 79 and a shorter return distance. This radical change in the distance travelled by chain 77 as it moves from sprocket 73 to sprocket 79 increasing the distance of the upper portion of travel while correspondingly reducing the distance of the lower portion of travel, causes a reversal of conveyor 39. This results as sprocket 79 will not turn clockwise to force conveyor 39 to move in the direction of arrow 59 but sprocket 79 will turn briefly counterclockwise and hence will cause the conveyor 39 to move in the direction of arrow 60. When the chain 77 has finished its movement and has reached the dotted position of FIG. 3, the chain 77 will reverse the above action and conveyor 39 will again be driven in the direction of arrow 59.

When the knife blade 65 has severed the mat the timing means to be hereinafter described causes activation of air cylinder 68 to raise the lower edge 64 of blade 65 from a position below the horizontal plane of mat 23 to its horizontal position as shown in heavy lines in FIGS. 2, 5 and 6. When the knife is raised, the conveyor section 39 as hereinbefore described will have been reversed so that the mat on the left side of the blade as viewed in FIG. 6 will have been pulled away from the knife blade 65. Since the conveyor 40 has constantly moved in the direction of arrow 53 the mat 23 will have pulled away from both sides of the knife and the knife will be free to raise without carrying with it the ends of the severed mat that, being impregnated with a binder, is tacky. This has been found to be most important as chain 77 returns to its normal full line position.

11 the damp,'uncured fibrous mat has a tendency-to adhere to a metallic surface and if it were not pulled away from from the knife blade, it would tend to follow the blade as it was lifted upward.

The timing of the reversing means 76 is such that a return of the direction of movement of conveyor 39 to its original direction as shown by arrow 59 will take place just after the timing means has elevated knife blade 65. When a sufficient period of time has elapsed so that knife 65 has cleared above mat 2.3,the timing means will cause a second activation of the cylinder 164, When this occurs, chain 77 is returned to its full line position as the downward force exerted by the piston 1117 in the direction of arrow 108 is released. Piston 1117 will actually be raised or thrust in the direction of arrow 111 so that all parts slowly return from their dotted line position in FIG. 3 to their full line position in FIG. 3. The spring 105 which was extended or stretched when the arm 95 moved from its heavy line position to its dotted position,

now pulls downwardly on arm 95 to supply the positive action on chain 77 to return it and all connected parts to their original heavy line position as shown in FIG. 3. When the above action takes place, it is seen that an effect opposite to the aforementioned action, which caused the reversal of sprocket 79, will be exerted on sprocket 79 as the distance of travel of the lower section of chain 77 is now increased while the distance of travel of the upper section of chain 77 is being diminished. Therefore, sprocket '79 will rotate at a slightly greater speed, than normally developed by chain 77, as the chain is I moving to return to its full line position and this acceleration of sprocket 79 will continue until the chain 77 rei-turns to its extended full lineposition. The result of this acceleration means that the conveyor section 39 will be travelling at a slightly greater speed in the direction of arrow 59 than will the conveyor section 46 by travelling in the direction of arrow 53 and this causes a bunching or slight overlapping of the material on the conveyor 40 onto itself. However, this bunching or overlapping quickly ceases and the mat returns to an even and normally horizontal flow across conveyors 39, 40 when the This overlapping of mat '23 onto itself is a natural consequence and balances out for the slight reversal of the movement of conveyor belt 39 so that the total volume movement of the fibrous mat 23 will remain constant fromthe forming station A to the shearing station B over a given operating period. If this acceleration and overlapping were not present then by constantly reversing the direction of the conveyor section 39 the size of loop 6 1 would continue to grow and eventually the size of loop 61 would become undesirably excessive.

Therefore by the compensating reversing and accelerating action of the conveyor section 39, the'lost volume flow of the mat 23 caused by constant cyclic reversal of conveyor 39 is regained by'brief subsequent acceleration of belt 39 to balance'the reversal and the mat 23 therefore .will move continuously and evenly from the forming section A through the shearing section B.

As the fiber mat 23 passes from the shearing station B,'the conveyor 40 moves the severed sections to station C. Referring to FIG. 2 it is seen that an additional con veyor belt 112, supported between rollers 113 and 114 keyed on shafts 115, 116 respectively is driven by a belt or chain 117 extending from a sprocket 118 on shaft 115 to'sprocket 56 on shaft 51 and carries segment 119 to station C. If desired, rather than using an additional conveyor, the conveyor 41) could be extended towards station C so as to include that portion of the conveying system supplied in FIG. 2 by the additional conveyor 112.

At station C the individual segments 119 having been sheared from the continuous fiber mat 23 are wrapped about a mandrel. Each segments movement is timed so .in that end of the mandrel.

as to arrive at station C synchronized in cycle with the means 'to be now described'by which each segment of the mat is Wrapped about a mandrel. Referring now to FlGS. 7 through 15 inclusive, there is supported upon upright angle irons "126, 121 and 122 the apparatus for wrapping the fibers and also the baking oven 123 where activation of the binder occurs. As was the case in stations A and B only one of each pair of supporting uprights has been shown, it'being understood that a cornplimentary identical upright of each pair is positioned on each side of the conveyor path. This is shown in FIG. 8 where both supports are visible. A shaft 124 is supported in journal bearings'125 to extend between the opposed uprights 121 Mounted to this shaft 124 and keyed thereto at opposite ends, outside the path of the fiber material by suitable means, is a pair of sprockets 127, 128. Referring to FIG. 2, a second pair of opposed sprockets 129, 136 are mounted at station F on a shaft 131. A pair of link chains 132, 133 respectively, are supported in tension by means to be hereinafter described, to travel in a path defined by sprockets 127, 128 and 129, 136. The sprockets 129, 130 at station F are mounted on shaft 131 in a manner similar to sprockets at 127, 128 of station C, i.e. between opposed 'bars 122 of the framework of the apparatus. Drive motor 134 (FIG. 2) through the medium of a chain 135 engages sprocket 136, also fixed to shaft 131, to supply the power drive to the apparatus causing a rotation of the link chains 132, 133 and sprockets 127, 128, 129, 131), generally in the direction of arrow 137 of FIG.'2. Referring to FIGS. 8 and 12 at equi-spaced points along the chains 132, 133 and mounted to the chains by suitable links are a plurality of blocks 138, 139 projecting inwardly relative to the chains. The blocks are located and disposed op posits to each other on their respective chains.

Referring to FIG. 13, the block 133 is mounted to racket 141 by screws 141 and bracket is mounted to chain 133 by link pins 142. The block 138 has a center opening 14-3 to receive a pair of bushings 144 held by flanges 145 against lateral shifting. A shaft 146 extends through the bushings 144 and a gear 147 is fastened concentrically to the outer end thereof. The section 148 of the shaft 146 extending inwardly of the block 138 is tapered as a pyramid at its end 149 for a purpose to be later described. The block 139 FIG. 11 is mounted similarly to chain 133 by bracket 140, screws 141 and link pins 142. A shaft 150 extends through opening 151 in bearing block 139 and has a conically tapered tip section 152 mounted to shaft 150 by a pin 153. A coil spring 154 is compressed between a face of the block 139 and the opposite inner face 155 of the base of tip 152 to normally force the tip in the direction of arrow 156. A knob 157 is mounted at the other end of shaft 150, by a pin 158. If the knob 157 is moved in the direction of arrow 159, it causes the tip section 152 to be withdrawn in the direction of arrow 159.

Referring particularly to FIGS. 8, 11 and 14, suspended between each pair of blocks 138, 139 is a mandrel 161 which in the embodiment shown is hollow. Each mandrel has openings 161 in its ends 162 adapted to respectively engage the conical end 152 of shaft 156 and the pyramidal end 149 of shaft 146.

To position the mandrel the operator inserts the tip 152 into one of the openings 161 in the end of a mandrel 16$) and exerts a longitudinal pressure on the mandrel to compress spring 154. The other end of the mandrel is aligned with the mating shaft 146 and upon release of the pressure the mandrel is moved endwise by spring 154 so that the pyramid end 149 engages the opening 161 The pyramid end 149 forms a driving connection with the mandrel for a purpose which will be disclosed hereinafter.

Removal of the mandrels at station]? is likewise accomplished in much the same manner in order to facilitate the slipping of the final form of the fibrous casing from the mandrel, it has been found desirable to keep a thin coating of wax on the mandrel. This wax film both assists the pickup of the mat section 119 during Wrapping and also prevents the tacky fiber from sticking to the mandrel.

Referring now to FIG. 10, a plurality of mandrels 160 are positioned as indicated at equi-spaced points along the entire length of chains 132, 133 and suspended therebetween in opposed equi-spaced blocks 138, 139. Referring to FIGS. 8, 9 and 13 mounted to shaft 124 is a gear 162'. This gear 162' is spaced by a shoulder bearing 163 from a sprocket 163'. Both the sprocket 163 and the gear 162' are free to rotate independent of the direction of rotation of shaft 124 by reason of their mutual connection to shoulder bearing 163. Referring to FIG. 13, there is shown further that a shoulder bearing 164 separates sprocket 127 from gear 162 and a shoulder 165 separates a bell crank arm 166 from the framework 129, being kept in position by pin 168 extending through the hub of sprocket 127 and shaft 124 and by collar 167 (FIG. 11) separating bell crank arm 173 from sprocket 128. As seen in FIGS. 2 and 7, the drive motor 169 is connected by a drive chain 170 to sprocket 163 and causes sprocket 163' and gear 162 to rotate in the direction of arrow 171 (FIG. 9).

Referring again to FIGS. 8 and 13, it is seen that the gear 147 mounted on each mandrel supporting shaft 146 will engage the teeth of the sprocket 162' at a specified time. As was hereinbefore pointed out the blocks 138, 139, equi-spaced opposite each other along chains 132;, 133 support mandrels 160 therebetween held by the inwardly directed tapered end points 149, 152 of rotatable shafts 150, 146. Referring to FIG. 9, it is shown that as these mandrels 160 move with chains 132, 133 the gear 147 will be engaged to gear 162 riphery and the counterclockwise rotating gear 163' will cause gear 14-7 to rotate clockwise while so engaged. This will in turn mean that each mandrel 160, as its gear 147 engages gear 162' will be rotated in a clockwise direction. Each mandrel 168 is therefore rotated about its longitudinal axis maintained in correct longitudinal position by tapered points 149, 152 resting in the center openings 161 of the ends 162 of the mandrel. As seen in FIGS. 8 and 9, a pair of bell-cranks 166, 173 each consisting of upper arms 174, 175 and lower arms 176, 177 yoked together to rotate in unison on bearings 178 (FIG. 11) mounted on shaft 124. Since the two bell cranks are identical only one will be described in detail, it being understood similar construction is present in its companion. Referring to FIGS. 8, 9, 10, 11 and 12, the bell crank upper arms 174, 175 are bifurcated to form an opening 179 between secondary arms 180, 181. Mounted to secondary arm 181 of both cranks by mounting screws 182, 183 are plates 184, 185 having toothed racks 186, 187 the teeth of which extend into the openings 179 of the bell crank arms. A shaft 188 pushing through the openings 179 has gears 189 and 190 mounted at its ends and the gears are held against lateral shifting by collars 191, 192 as they engage the racks 186, 187.

This shaft supports a forming roller 193 that extends transversely of the direction of movement of the mandrels and which is slightly shorter in length than the mandrels 160. This forming roller 193 being fixed to the shaft will rotate with the freely rotatable shaft 188 when a force is imparted to it. The gears 139, 199 as seen in FIGS. 9 and 11 are secured to the shaft 188 by pins 194 so that the gears 189, 190, the shaft 188 and the forming roll 193 form a unitary structure.

It is seen in FIG. 9 that the bell cranks 166, 173 hold the forming roller 193 in the path of the mandrel 160 as the mandrel follows that path defined by the chains 132, 133 and the mandrel periphery comes into close promixity to the forming roller periphery as is best shown in FIG. 2. At the same moment the conveyor 112 has for about 180 of its pedelivered into the nip formed between the periphery of mandrel and the periphery of forming roller 193 the lead edge of a segment 119 of the severed mat. As was hereinbefore described each mandrel 1611 is moving along the path of the chain in the direction of arrow 137 and through the engagement of gears 147 with gear 162' the mandrels will rotate about their longitudinal axis in a clockwise direction. When the mat segment 119 is acted upon by the rotating mandrel in the nip between forming roller 193 and mandrel 160 the segment is drawn or wound about the mandrel and the forming roller 193 rotates as a backup roller in a counterclockwise direction. The mat segment 119 is therefore subject to pressure while being wrapped around mandrel 161) through the weight of roller 193. This pressure applied the full length of the mat segment blends the fibers intimately as the pipe covering is formed to prevent the formation of layers during the wrapping. By replacing the roller 193 if desired with either a heavier or lighter roller the amount of the pressure may be varied according to the conditions of pressure as determined by manufacturing requirements. In addition this pressure continues for a period of time during which the forming roller 193 and mandrel 160 are locked to one another, after the mat is wrapped about the mandrel and carried together along the path of the mandrels defined by chains 132, 133. Therefore, when the Wrap of segment 119 about mandrel 161) is completed, roller 193 bears against the peripheral surface area of the formed pipe covering to smooth the peripheral surface and to cause the trial edge of the segment which is tapered, to be blended intimately into the peripheral surface.

In order that the wrap of material about the mandrel is made under constant pressure it is necessary to provide a means whereby the forming roller will remain flush to the mandrel and fiber material being wrapped thereabouts until the wrap is completed as the diameter of the casing being wrapped increases. Also means are required to reposition the forming roller so that it will be in position to repeat the process With each succeeding mandrel moving along between constantly moving chains 132, 133 as seen in FIGS. 2, 9 and 10.

Mounted to the upper arm of the crank 173 is a bracket 194' (FIGS. 10, 11 and 12) fastened by screws 195, 196 which supports the means which serves as a temporary connection to synchronize movement of the roller 193 and the mandrel 1611 to carry both along together while the bell crank 166 moves from its heavy line position of FIG. 10 to the dotted line position of FIG. 10. An arm 197 extending substantially tangentially to the periphery of the sprocket is attached to a sheath or sleeve 198 which is about a shaft 199. The shaft extends from the bracket 194 inwardly over the path of chain 133. At the extremity of the arm 197 is a camming pin 299 which extends over the path of chain 133 in a position to engage the surface of a cam 281 that is suitably mounted by screws 292 to a cross angle iron bar 2113 which forms part of the framework of the apparatus. The extremity of the arm 197 is bifurcated to receive a downwardly extended dog hook 204 held in place by pins 205, 206. A tension spring 2117 connected between the arm 174 and an upwardly extended bar 208 joined to sheath 198 normally holds the hook in its solid line position as seen in FIG. 10 and in its dashed line position as shown in FIG. 12. As the mandrel 160 is carried along its path each block 139, in turn, will engage the dog hook 284 so that the bell cranks 166, 173 move with the mandrel 160. This engagement takes place at the same time the mandrel 168 is rotating, as hereinbefore described, so that the mandrel engages the roller 193 forming a nip therebetween to draw the individual and successively delivered fiber mat sections 119 about the mandrel. When the block 139-hook 2114 engagement has raised the bell cranks from the full line position to the dotted position (F1689 and the pin 2110 will be cammed upwardly by the action of the camming plate 281. As this occurs the hook'204 will be released from the block 139 so that the bell cranks are released whereby arms 166, 173, and forming roller 193 therebetween, will both by reason of their own weight return to the solid line position of FIGS. 9 and 10. As the rotation of the mandrel 168* causes the mat to be wrapped around the mandrel, it obviously follows the wrapped casing will increase in diameter progressively as the fiber mat is wrapped. As this diameter increases, the forming roller 193 is caused to walk upwardly by cams to be hereinafter described and gears 189, 190 engage the racks 186, 187 of plates 184, 185. The roller 193 bearing against the rotating mandrel is mounted so that it is free to move upwardly with respect to the mandrel 166 as the material is wrapped about the mandrel. When the mandrel 16,8 reaches the fully raised position indicated in dotted outline in FIGS. 9 and 10 the wrap will have been completed and after it rolls the outside periphery to smooth the casing the forming roller 193 may be released to return to its rest or mandrel aligned position where it will be positioned to engage a subsequent mandrel carried by the chains 132, 133.

In this manner a continuous recycling of the apparatus is secured so that each mandrel as it moves to receive the section 119 of fibrous mat engages and lifts the forming roller 193 with the mandrel for a prescribed period of time. Then by the camming action above described the bell cranks 166, 173 supporting this roller will be released to reposition roller 193 for the subsequent mandrel. Connecting the lower bell crank arms 176, 177 is a shaft 2119 (FIGS. 8, 9 and 10) having a yoke 210 mounted intermediate its length connected to the piston rod 211 of air cylinder 212. The air cylinder is fixed by means of a shaft 213 between two upstanding brackets 214, 215 so as to be pivotable relative to itself. The brackets 214, 215 are welded orotherwise suitably mounted to a cross bar 216 which interconnect the angle irons 120. The mounting of cam 291 is accomplished through a connecting arm 217 by means of screws and bolts 202. The cam 281 is longitudinally shiftable for adjustment as the screw shafts extendthrough the longitudinal slot 218 (FIG. 12) and this adjustment controls the moment that forming roller 193 will be released from dog 204.

In order to maintain the shaft 188 about which the forming roller freely rotates from being ejected from the bifurcated ends at bell cranks 166, 173, a safety or holding plate 219 is mounted to the upper ends of hell arms 17.4, 175 by means of screws 22%. This also forms an upper limiting stop for the hereinabove discussed walking action of roller 193. Air cylinder 212 provides a cushioning action to counteract the'falling forming roller 193 suspended between'bell cranks 166, 173 which falls under its own weight. Also after the bell cranks 166, 173 have fallen almost all the way the cylinder 212 provides positive pressure to position the bell cranks 166, 173 and forming'roller 193 to align them relative to the succeeding mandrels so that the subsequent sections of the fibrous mat will bedrawn into the, nip between roller 193 and mandrel 160 and onto the mandrel 160. It is important that this relationship between the forming roller and mandrel be maintained to be sure that the proper and constant wrap of a fiber mat section 119 will be made about the mandrels. From the description hereinabove set forth, it is therefore seen that the forming roller 193 moving with the rotating mandrel 160 directs pressure downwardly on the mat section 119 by reason of its weight as the mat is wrapped about the mandrel. This results in a constant wall thickness of the pipe covering as it is formed about the mandrel and prevents variations in wall thickness or insures peripheral evenness.

In order to maintain the chains 132, 133 in tension, means for tightening the tension are provided on each side of shaft 124. Since the same structure appears. on both as the fiber increases the all over 1% sides only that present on one side has been shown in detail. Referring to FIGS. 11, 112 and 15, an opening 221 is formed in the framework :by cross bars 203 and 222 which are joined by vertical angle irons 223 and frame upright 129. The journal is surrounded and integraliy attached to a slidable plate 224 which has longitudinal key slots 225, 226 which ride in vertical tracks 227, 228 welded to the angle irons 222, 2193 respectively. A hollow lug 229 (FIG. 12) integrally joined to plate 224 has an internally threaded sleeve 230. A hexagonal headed screw 231 extends through a nut 232 welded to the side of the frame support 128 and continues through the sleeve 230 to terminate at the hollow center of the lug 229 where the end is secured by a washer and a cotter pin. By adjustment of screw 231 the plate 224 will move journal 125 longitudinally with respect to the frame to properiy tension the chains 132, 133. The journal construction on opposed sides of the frame is identical. Other conventional means can be used such as weights instead of screws 231 to achieve tension in chains 132, 133 without departing from the scope of the invention.

As the sections 119 are wrapped about the mandrel the pressure of the forming roller 193 causes the feathered edges to be pressed flat against the body of the pipe covering as hereinbefore described so that it becomes almost impossible to visually determine where the section starts or stops in the cylindrical form. This insures an even wall thickness around the entire circumference of the pipe covering. To assist in the control of this pressure exerted by the forming roller 193 against the mandrel 160 as it receives the fiber mat section 119, the gear 189, 191i and rack 186, 187 arrangement allows the roller shaft 188 to walk-up between bifurcated arms 174, has been hereinbefore described. However, to provide even pressure on the mat so that the weight of the forming roller is sufficient only to smooth form the pipe covering and is not excessive to a degree sufiicient to compress the fibers, a pair of cam plates 234, 235 (FIGS. 8, 9 and 11) are adjustably mounted from a pair of blocks 236 which in turn are welded to the framework cross bars such as 203. Forming roller cam plates are adjustable for a purpose to be later described and the hubs of gears 189, 191) ride on the cam edge 237 of these plates. This adjustability is secured through suitable retaining screws 238, 239 which engage the plates 234 to block 236 through slots 240, 241. Similar screws (not shown) are provided to adjust the plate 235 so that plates 234 and 235 may be aligned with respect to each other. In this way the shaft 188 is positively raised and the distance between the circumferential surface of roller 193 and the circumferential surface of mandrel 160 is gradually increased diameter of the wrapped casin The roller 193 therefore bears downwardly against the fibrous material as it is being wrapped about the mandrel 160. The portion of the weight of this roller 193 which presses against the tacky fiber mat is sufficient to provide a pipe coverin in normal operation which has a density of three pounds per cubic foot or less. The cams 234, 235 are shaped, in the embodiment shown, to lift the roller gradually with relation to the rotational axis of mandrel 160 to maintain a constant weight on the wrapped material and at the same time to compensate for the progressively increasing thickness of the material. It follows that forming roller 193 by adjustment of cams 234,

235, or by varying the shape of the cams, may be caused to exert greater pressure at any selected moment of the wrapping period so as to compress the fibers more fully at any selected portion of the casing, i.e. at the middle of the pipe covering or at the outer shell. The forming roller 193 does not freely rest on the material although it contacts the material and is so rotated through this contact, but strictly speaking, the roller 193 rests against the material and exerts through its own weight pressure against 

1. IN THE FORMATION OF A GENERALLY CYLINDRICAL FIBROUS CASING HAVING SUBSTANTIALLY UNIFORM THICKNESS WHEREIN SAID GENERALLY CYLINDRICAL FIBROUS CASING IS NOT CONFINED WITHIN MOLDS DURING THE CURING OF THE BINDER THEREIN, THE METHOD COMPRISING: (A) FORMING ON A MANDREL A GENERALLY CYLINDRICAL FIRBOUS CASING OF SUSBTANTIALLY UNIFORM THICKNESS IMGREGNATED THROUGHOUT WITH UNCURED HEAT-CURABLE BINDER. (B) APPLYING SUFFICIENT HEAT TO THE PERIPHERAL SURFACE OF SAID FIBROUS CASING BY CONTACTING SAID PERIPHERAL SURFACE WITH A HOT BODY TO CONTACT CURE THE BINDER IMMEDIATELY ADJACENT SAID PERIPHERAL SURFACE TO FORM A SUBSTANTIALLY RIGID SHELL ON SAID FIBROUS CASING PRODUCING A FIBROUS CASING OF SUBSTANTIALLY UNIFORM THICKNESS ON WHICH SAID RIGID SHELL PROVIDES A SUBSTANTIALLY CYLINDRICAL EXTERNAL PERIPHERY, (C) SEPARATING SAID FIBROUS CASING AND SAID HOT BODY, (D) CURING THE BINDER IN THE REMAINING PORTIONS OF SAID FIBROUS CASING WITHOUT CONFINING THE FIBROUS CASING IN A MOLD AND WHILE MAINTAINING AT LEAST PORTIONS OF THE SHELL FREELY EXPOSED, AND (E) RELYING UPON SAID SUBSTANTIALLY RIGID SHELL TO MAINTAIN THE EXTERNAL SHAPE AND THE SUBSTANTIALLY UNIFORM THICKNESS OF SAID FIBROUS CASING DURING SAID CURING OF THE BINDER IN SAID REMAINING PORTIONS OF SAID FIBROUS CASING. 